(1) Field of the Invention
The invention concerns an electric drive (1) with a circuit board (2), having conductor tracks (3) and contact openings (4) with plated through-holes (5) and equipped with electronic components (6). The circuit board (2) is coated with a protective layer (7) of insulating material, and press-fit contacts (8) are inserted into the contact openings (4) and in the electrical contact areas (9) within the contact openings (4), electrical contact exists between the press-fit contact (8) and the plated through-hole (5) of the contact opening (4).
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Protection of circuit boards by parylene coating has proven itself to be a hydrophobic, chemically-resistant barrier relative to inorganic and organic media, strong acids, alkalis, gases and water vapor. Parylene is an excellent electrical insulator with high voltage strength and low dielectric constant. The protective coating is applied to the substrate as a pore-free and transparent polymer film in vacuum by condensation from a gas phase (CVD process/chemical vapor deposition). The process has the result that the polymer coating fully encloses the circuit board, so that subsequent electrical conduction thus far only appeared to be possible after additional machining steps. According to the prior art, electrical connection sites have thus far been protected by applying a masking material before the CVD process. As an alternative, the parylene coating can be partially ablated with a laser beam, or can also be removed mechanically. These additional construction steps increase manufacturing costs and manufacturing risks.
Press-fit electrical contacting has established itself as an economical contacting possibility for uncoated circuit boards. Commercial press-fit electrically conductive contacts are then inserted into the contact openings by a simple insertion process and, in so doing, form a permanent reliable contact and an electrical connection without additional soldering or welding processes.